Double-acting hollow-plunger pump



Aug. u, 1925.

E. T. ADAMS ET AL DOUBLE CTING HOLLOW PLUNGER PUMP Patented Aug, 11, 19275.

UNITED sTATEs PATENT oFFlcE.-

.EDWARD T. ADAMS, or Los ANGELES. AND .IoIIN B. REILLY', or WHITTIER, CALIFOR- NIA, AssIGNoEs To JOSEPH G. y. RICHARDSON, or Los ANGELES, CALIFORNIA.

'DOUBLE-.ACTING- HOLLOW-PLUNGER PUMP.

Application filed August 27,` 1924. Serial No. 784,408.

To all 'whom it may concern! Be it known that we, EDWARD T. ADAMS and JOHN B. REILLY, citizens of the United States, and residents of Los Angeles, California, and Whittier, California, respectively, have invented new and useful Improvements in Double-Acting Hollow-Plunger lumps, of which the following is a specification.

The present invention relates to deep well pumps of that general type in which there is provided a so called standing tube, while the plunger is made up of two other tubes; one working inside ofthe standing tube and the other working outside of the standing tube. The result is that an annular space exists between the two plunger tubes; said space 'increasing in volume with the outward' stroke of the plunger and decreasing with the inward stroke of the plunger. The above described arrangement of tubes protvidesa labyrinthine path through which fluid must travel before it can pass the plunger, and as a consequence it is generally believed that the leakage or slip is thereby reduced. However, the incompressible iiuid leaking into the annular space during outward movement of the plunger must be displaced therefrom during the inward stroke of the plunger in lrder to allow the plunger.

to descend. The energy yrequired to force the fluid out again is practically wasted, and in addition, some of the oil is forced to pass the plunger and leakage is thereby actually encouraged.

Another outstanding advantage of`such pumps is that sand will find its way into the annular space and will remain there, eventually preventing proper descent of the plunger and finally stalling the pum In the pump shown by Miller in his atent No. 1,483,369, a plurality of ports are provided in the innermost plunger tube so that the annularl space is vented. The objection to Millers pump is, that in p erforating the inner plunger tube, one of the objects of the tube is defeated. In other words, fluid reaching the annular space by leakage' may pass directly through the ports without appreciable resistance, whereas, if the ports vwere not there, such fluid before reaching the interior of the inner plunger tube, would have to pass through the. small' working clearanceY between the inner plunger tube and the standing tube.

It is the prime object of the invention to provide improvements in pumps of the above mentioned type-wherebythe annular space may be properly vented for ejection of leakage and sand, without defeatingthe purpose of the inner plunger tube.

Another object of the invention is to provide a pump in which the resistance to leakage is increased over previous pumps of the above mentioned type, particularly inasmuch as it is advisable to allow large working clearances without greatly reducing the efficiency of the pump.

Another object of the invention is to provide l'means Iwhereby the increasing volume of the annular space does not cause an abnormal pressure reduction to the extent that leakage is actually encouraged. Still other objects and advantages willappear hereinafter.

We have illustrated by the accompanying drawings a preferred embodiment of our invention.

Inl the said drawings:

Figure 1 is a viewl in vertical section of the said embodiment;

Figure 2 is a View in section seen on a line 2-2 of Figure 1;

Figure 3 is a view in section thereof seen on a line 3 3 of Figure 1.

In carrying out this form of invention we provide an annular casing wall 5 which incloses the pump chamber B. The wall lis provided at the lower end with a closure wall 6, having a central upwardl ranging suction aperture A. Aperture' terminates at an annular valve seat 9 on which rests a ball 10. The valve seat and ball are hereinafter referred to as the standing valve. It will be understood that the pump casing continues u ward to connect with discharge tubing, not shown) which leads to the surface to provide a continuous fluid course intoand through which fluid handled by the pump, is carried to the surface.

The bore A of the well is lined with casing 11. The pressure of oil contained in A creasing in volume, durin B will always be considerably inexcess of the pressure in A and A.

The pump is provided with a reciprocal plunger head 12 Vfrom which depends an annular wall 14.' Said wall is hereinafter referred to as the outer plunger wall, and its outer diameter is appreciably less thanthe inner diameter of the pump casing, so that -solid matter, such as sand, may settle into space B.

To the plunger head there is attached a common ball cage 15, having an externally threaded boss 16 whereby the plunger mayone-way communication with A through the` standing valve. An inner plunger' wall 18 is provided which depends from the plunger and which is a working fit within the standing tube. Inlconformance with a salient feature of the invention, a valve seat 19 is provided within the inner plunger wall, and upon said seat there reposes a ball 21 which is limited in its upward movementby a transverse pin 22. It will be apparent now that as the plunger walls are reciprocated relative to the pump casing, that the inner plunger wall will co-act with the standing tube int the same way in which a plunger ordinarily co-acts with a stationary pump barrel. In other words, during the up stroke of the plunger space C will increase in volume and become filled with oil and during the down stroke the working valve carried by the inner plunger wall will be moved downward through the oil; the standing valve preventing oil which has reached C from returning to A. An annular space E exists between the inner and outer plunger walls, into which space the standing tube extends.

It will be observed that while space C is increasing in volume space E will also be in'- the up stroke. During the down stroke t ese spaces will decrease in volume. The inner plungerA wall is provided with a plurality of ports -leading into space E, as in the case of the pumps mentioned heretofore. For thepurpose of preventing fluid flowing from points above the pump back throughlthe ports 23 to.space E, we provide a ball` 25 resting on the seat' provided by the upper valve cage.

The operation of the pump will be understood from the following: During the upstroke of the plunger space C increases 1n volume and oil is induced therein through iiuid or gas existing therein will be reduced.

p Fluid cannot flow from B into the space E becauseof the ball 25; the ball therefore serving to prevent slippage from B back into E. The space E will therefore draw fluid from the'space D, which is internally of theinner plunger wall. This space D can be supplied with oil only throughthe lower working valve and standing valve. Therefore during the up stroke of the pump the plunger is not only acting to draw oil through the standing valve into the spacel C, but it is also acting to cause oil to flow4 into the space E from C, through the working valve. The fact that the standing valve and lower working valve are both open during the up stroke :of the plunger' is an advantageous peculiarity of this pump.

In other words, space E is really an auxiliary pump chamber.I stroke of the plunger, which would be ineffective for displacing oil were it not for the space E, said space is decreased in vo1- ume and a part of the oil contained therein.-

is forced outwardly. This oil is double checkedfrom flowing downwardly because of the two valves below the port. Therefore, the oil displaced will be forced through the ports and will raise ball 25 and be forced During the down upward throu'gh the pump casing and tubing. It will be apparent now that we have provided a pump having two pumping chambers, in' which pump the up stroke of the plunger is the suction stroke for both pump chambers, whereas the down stroke of the plunger is a discharge stroke for one of the chambers while the up stroke is the discharge for the other chamber. Or, in other words, we have provided a double pump in which a double suction stroke and a single discharge stroke is accomplished by the upward movement of the plunger while the second single discharge stroke is accomplished by the down stroke of the plunger.

Any sand or silt which may settle from the oilcontained in B would tend to lodge upon the cylinder head and eventually find its way 1nto space B. Of course a certain amount of leakage will exist between the co-acting annular walls of the casing and plunger' respectively, and we will now con- Sider the operation of the pump in so far as leakage, and self-cleaning features are concerned. In the following discussion two conditions will be assumed, namely, that in which a slippage between the casing wall and the outer plunger wall is slight, and that in which such leakage is excessive to the point that it will flow into space E as rapidly as space E is increased. It will be understood that during the down stroke of the plunger all the chambers within the pump are subject to the maximum pressure and there can'be no leakage from B to E or from B to C by way of E; providing of course the valves are ti ht. In the instance where the leakage is sllght space E will be subject to a suction pressure which will be substantially that of the pressure then existing in space C and as a consequence there will be no tendency for oil to leak from E to C by way of the space between the innery plunger wall and the standing tube. Of course during the upward stroke space E is of reduced pressure and therefore there may be leakage from B into E. This leakage will carry the sand from theplunger head into the lower portion of space E. As oil is drawn into E from D during the up stroke of. the pump the oil contained in E will be considerably agitated and will pick up sand which has found its way to the lower part of space E. .The sand in suspension with the oil will be ejected, during the down stroke of the pump, from the space E, throu h the ports and into the column of oil which is then rising relatively through the fluid course D. The conclusion to be drawn from the foregoing, is that with normal leakage no sand or oil will find its way from B to C`by way of the space E and therefore any tendency of the space C to become clogged with precipitated sand is practically precluded.

Assuming a condition yin which leakage is excessive from B to E: during the up stroke of the plunger space E will increase in vol.- ume but will not draw any oil from D or C or A because of the fact that the volume of E is filled with leakage as rapidly as that volume is created. \It is therefore apparent that during the up stroke of the cause ofthe fact that the prime condition to` be avoided is that of carrying sand past the plunger into internal chambers of the pump such as C.' By preventing sand from passing through the clearance between the inner plunger tube and the standing tube the life of the wearing surfaces will be greatly increased. It is to be noted particularly that the leakage which is spoken of from E to C of space E until a down stroke is effective in displacing it through the ports.

In considering the advantages of this construction and the resistance to leakage of the relatively reciprocating walls, it should be noted that there is considerable resistance offered to oil passing from space B to E. This resistance is that due to the small clearance between the standing tube and the outer plunger wall for a distance equal to the length; of the plunger. That amount of resistance is all of the resistance that is ordinarily offered usual pumps. In this case, however, oil having found .its way to E has only completed one-half of its journey to the space'C and therefore, before any oil can leak from .B to C it must pass through an exceptionally long and roundabout course which offers great frictional resistance, and in which course there is pro vided the intermediate enlarged volume E which tends to collect the sand. While the ports are open at all times from E to D the upper valve 25 serves as a check to prevent oil from flowing from B through the ports into E, while the lpwer valve 'prevents oil'taking al short cut from B to C vby way of the ports.

We claim:

1.' In a pump, a pump casing the interior of which is subject to the discharge pressure of the fluid pumped, an outer annular wall to said casing, an inner annular wall to said casing providing an intermediate anf .nular space, a plunger member including an inner wall and an outer wall spaced apart and jointly reciprocal to provide a space into which the inner wall of the casing extends while acting to increase and decrease the effective volume of the annular space v as the plunger is reciprocated relative'v to the casing walls, the inner wall of the plunger providin a central fluid course, a pair of spaced ilischarge valves in said, course, and a port leading from the 'annular space to said central bore at a point between the said two discharge valves.

2. In a pump, a pump casing the interior of which is subject to the discharge pressure of the fluid' pumped, an outer annular wall to said casing, an .inner annular wall to said casing-providing an intermediate annular space, a plunger member including an inner wall and an outer wall spaced apart Y spaced discharge valves in saidl course, and

a port leading from the annular space to said central bore at a point between the said two dischargevalves, and establishing constant communication therebetween.

8. In a pump, a pump casing the interior of which is subject to the discharge pressure of the fluid pumped, an outer annular wall to said casing, an inner annulanwall to said casing providing an intermediate annular space, a plunger member including an inner wall and an outer wall spaced apart and jointly reciprocal vto provide a space into which the inner wall of the casing'extends while acting to increase and decrease the effective volume of the annular space as the plunger is reciprocated relative' to the casing walls, the inner wall of\ the plunger providing a central uid course, a pair o t' spaced discharge valves in said course, and. a port leading from the annular space to said central bore at a4 point between Vthe said two discharge valves, the casing walls and plunger Walls so arranged that oil may escape from oints immediately external of the inner casing wall to points within the inner casing wall only by way of the working clearances existing between the corresponding adjacent relatively Teciprocal walls of the casing'and plunger respectively.

4. In a pump, a pump casing the interior of which is subject to the discharge pressure of the fluid pumped', an outer annular wall to said casing, an inner annular wall to said casing providing an intermediate annular` space, a plunger member including an inner wall and an outer wall spaced apart and jointly reciprocal to provide a space into which the inner wall of the casing exjtends while acting to increase and decrease the eiective volume of the annular space as the plunger 1s reciprocated relative to the casmg walls, the inner wall of the plunger providing a central fiuidcourse, a pair of spaced discharge valves in said course, and a port leading from the annular space to said central vbore at a point between the said two .discharge valves, and establishing constant communication therebetween, the casing walls and plunger walls "so arrangedthatioll may escape from points immediately external of the inner casing wall to v,points within the inner` casing 'wall only by way of the working clearances existing between the correspondingadjaccnt relatively reciprocal walls of the casing and plunger, respectively.

5. In a pump, two relatively reciprocal creases and decreases with relative recipro cation of the members, the innermost of the walls providing a central fluid course, and spaced discharge valves within said fluid course, one of the walls being provided with a constantly open port leading from the said otherwise isolated space into the fluid course at a'point intermediate of the two valves.

6. In a pump, two relatively `reciprocal members, each member having two spaced concentric annular walls, each of the walls of one member being disposed in close proximity to a corresponding one of the `walls of the other member whereby an isolated annular space is provided which increases and decreases with relative reciprocation of the members, the innermost of the walls providing a central fluid course, a suction nonreturn valve carried by one of the said members and opening upwardly into said fluid course, a discharge valve carried by one wall of the other member', an upper discharge valve carried by said member, and a port provided in the Wall of said member leading from the annular space into the central` fluid course between the two discharge valves.

7. In a pump, two relatively reciprocal members, each member having two spaced concentric annular walls, each of the walls of one member being disposed in close proximity to a corresponding one of the walls of the other member whereby an isolated annular space is provided which increases and decreases with relative reci rocation of the members, the innermost o the walls providing a central `iuid course, a suction valve and a discharge valve arranged to coact with the relatively reciprocating members to provide pumpin action, a port leading from said centra Huid course to said annular space, and means acting to prevent fluid fiowing from said annular spaceto said suction valve by way of said central fluid lll course while permittingfluid to surge con the casing members. to provide a main pump chamber and an auxiliary pum chamber separatedfrom the mainpump c amber by one of aforesaid tubular members, a standing valve, a pair of spaced working valves car- `fluid in said :Huid course, Y trating the inner tubular ried by said plunger," and a port leading from said auxiliary pumping ohamberAto.

said main pumping chamber, through that member which separates said ohambers,. intermediate of the said working valves.` I L 9. A pump plunger for pumps of the character described, embodying an outer tubular member and an inner tubular mem ber; said plunger providing a central duid course, a pair of spaced upwardly opening nonreturn valves for controlling low of and a'port penemember at a point intermediate of the said two valves. v K

10. In a pump, a pump'casing having an inlet opening at its lower end provided with a standing valve, a standing tube extending upwardly from said standing valve and lspaced from said casing, a plunger provided with inner and outer walls sliding respectively on theinside and outside of the standing tube so as to form a main pump hamber within said inner plunger Wall and an auxiliary pump ,Chamber between said inner and outer plunger walls; said inner plunger ,wall being provided with a port establishing permanent communication between said main and auxiliary pump chambers, a working valvecarried by said^inn`er plunger wall above said port, and a working'valve oarried by said plunger Wall below said port.

EDWARD T. ADAMS. JOHN B. REILLY. 

